package com.td.framework.webmanager.common;




/**
 * 
 *  Title:md5加密类
 *  Description: md5加密
 *  Copyright: Copyright (c) 2008 
 *  Company 北京水软科技有限公司
 * 
 * @author FLT006
 * @version 1.0
 */
public class MD5 {

    /* 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的,这里把它们

    /* 实现成为static final是表示了只读，切能在同一个进程空间内的多个Instance间共享*/

    static final int S11 = 7;

    static final int S12 = 12;

    static final int S13 = 17;

    static final int S14 = 22;



    static final int S21 = 5;

    static final int S22 = 9;

    static final int S23 = 14;

    static final int S24 = 20;



    static final int S31 = 4;

    static final int S32 = 11;

    static final int S33 = 16;

    static final int S34 = 23;



    static final int S41 = 6;

    static final int S42 = 10;

    static final int S43 = 15;

    static final int S44 = 21;



    static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0,

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

    /* 下面的三个成员是MD5计算过程中用到的3个核心数据，在原始的C实现中 */

    /*   被定义到MD5_CTX结构中 */

    private long[] state = new long[4];  // state (ABCD)

    private long[] count = new long[2];  // number of bits, modulo 2^64 (lsb first)

    private byte[] buffer = new byte[64]; // input buffer



    /* digestHexStr是MD5的唯一一个公共成员，是最新一次计算结果的16进制ASCII表示. */

    public String digestHexStr;



    /* digest,是最新一次计算结果的2进制内部表示，表示128bit的MD5值. */

    private byte[] digest = new byte[16];



    /*  getMD5ofStr是类MD5最主要的公共方法，入口参数是你想要进行MD5变换的字符串 */

    /*  返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．*/

    public String getMD5ofStr(String inbuf)

    {

        md5Init();

        try
        {
            md5Update(inbuf.getBytes(), inbuf.length());
        }
        catch(Exception e)
        {}

        md5Final();

        digestHexStr = "";


        for (int i = 0; i < 16; i++)

        {

            digestHexStr += byteHEX(digest[i]);

        }
        digestHexStr = digestHexStr.replace('z', 'a');
        digestHexStr = digestHexStr.replace('9', '1');
        return digestHexStr;

    }

    /* 这是MD5这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数. */

    public MD5()

    {

        md5Init();

        return;

    }



    /* md5Init是一个初始化函数，初始化核心变量，装入标准的幻数 */

    private void md5Init()

    {

        count[0] = 0L;

        count[1] = 0L;

        ///* Load magic initialization constants.



        state[0] = 0x67452301L;

        state[1] = 0xefcdab89L;

        state[2] = 0x98badcfeL;

        state[3] = 0x10325476L;

        return;

    }

    /* F, G, H ,I 是4个基本的MD5函数，在原始的MD5的C实现中，由于它们是 */

    /* 简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，*/

    /* 我把它们实现成了private方法，名字保持了原来C中的。 */



    private long F(long x, long y, long z)

    {

        return (x & y) | ((~x) & z);

    }



   private long G(long x, long y, long z)

   {

        return (x & z) | (y & (~z));



    }



    private long H(long x, long y, long z)

    {

        return x ^ y ^ z;

    }



    private long I(long x, long y, long z)

    {

        return y ^ (x | (~z));

    }



   /* FF,GG,HH和II将调用F,G,H,I进行近一步变换 FF, GG, HH, and II transformations */

   /* for rounds 1, 2, 3, and 4. Rotation is separate from addition to prevent recomputation. */



    private long FF(long a, long b, long c,

                long d, long x, long s,long ac)

    {

        a += F (b, c, d) + x + ac;

        a = ((int) a << s) | ((int) a >>> (32 - s));

        a += b;

        return a;

    }



    private long GG(long a, long b, long c,

                long d, long x, long s,long ac)

    {

        a += G (b, c, d) + x + ac;

        a = ((int) a << s) | ((int) a >>> (32 - s));

        a += b;

        return a;

    }



    private long HH(long a, long b, long c,

                long d, long x, long s,long ac)

    {

        a += H (b, c, d) + x + ac;

        a = ((int) a << s) | ((int) a >>> (32 - s));

        a += b;

        return a;

    }



    private long II(long a, long b, long c,

                long d, long x, long s,long ac)

    {

        a += I (b, c, d) + x + ac;

        a = ((int) a << s) | ((int) a >>> (32 - s));

        a += b;

        return a;

    }



    /* md5Update是MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个 */

    /* 函数由getMD5ofStr调用，调用之前需要调用md5init，因此把它设计成private */

    private void md5Update(byte[] inbuf, int inputLen)

    {

        int i, index, partLen;

        byte[] block = new byte[64];

        index = (int)(count[0] >>> 3) & 0x3F;

        // /* Update number of bits */

        if ((count[0] += (inputLen << 3)) < (inputLen << 3))

            count[1]++;

        count[1] += (inputLen >>> 29);



        partLen = 64 - index;



        // Transform as many times as possible.

        if (inputLen >= partLen)

        {

            md5Memcpy(buffer, inbuf, index, 0, partLen);

            md5Transform(buffer);



            for (i = partLen; i + 63 < inputLen; i += 64)

            {

                md5Memcpy(block, inbuf, 0, i, 64);

                md5Transform (block);

            }

            index = 0;

        }

        else

            i = 0;



        ///* Buffer remaining input */

        md5Memcpy(buffer, inbuf, index, i, inputLen - i);

    }



    /* md5Final整理和填写输出结果 */

    private void md5Final ()

    {

        byte[] bits = new byte[8];

        int index, padLen;



        ///* Save number of bits */

        Encode (bits, count, 8);



        ///* Pad out to 56 mod 64.

        index = (int)(count[0] >>> 3) & 0x3f;

        padLen = (index < 56) ? (56 - index) : (120 - index);

        md5Update (PADDING, padLen);



        ///* Append length (before padding) */

        md5Update(bits, 8);



        ///* Store state in digest */

        Encode (digest, state, 16);

    }



    /* md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把 */

    /* len长度的字节拷贝到output的outpos位置开始. */



    private void md5Memcpy (byte[] output, byte[] input,

            int outpos, int inpos, int len)

    {

        int i;



        for (i = 0; i < len; i++)

            output[outpos + i] = input[inpos + i];

    }



    /* md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节. */

    private void md5Transform (byte block[])

    {

        long a = state[0], b = state[1], c = state[2], d = state[3];

        long[] x = new long[16];



        Decode (x, block, 64);



        /* Round 1 */

        a = FF (a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */

        d = FF (d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */

        c = FF (c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */

        b = FF (b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */

        a = FF (a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */

        d = FF (d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */

        c = FF (c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */

        b = FF (b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */

        a = FF (a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */

        d = FF (d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */

        c = FF (c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */

        b = FF (b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */

        a = FF (a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */

        d = FF (d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */

        c = FF (c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */

        b = FF (b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */



        /* Round 2 */

        a = GG (a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */

        d = GG (d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */

        c = GG (c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */

        b = GG (b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */

        a = GG (a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */

        d = GG (d, a, b, c, x[10], S22, 0x2441453L); /* 22 */

        c = GG (c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */

        b = GG (b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */

        a = GG (a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */

        d = GG (d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */

        c = GG (c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */

        b = GG (b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */

        a = GG (a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */

        d = GG (d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */

        c = GG (c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */

        b = GG (b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */



        /* Round 3 */

        a = HH (a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */

        d = HH (d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */

        c = HH (c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */

        b = HH (b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */

        a = HH (a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */

        d = HH (d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */

        c = HH (c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */

        b = HH (b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */

        a = HH (a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */

        d = HH (d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */

        c = HH (c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */

        b = HH (b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */

        a = HH (a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */

        d = HH (d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */

        c = HH (c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */

        b = HH (b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */



        /* Round 4 */

        a = II (a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */

        d = II (d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */

        c = II (c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */

        b = II (b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */

        a = II (a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */

        d = II (d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */

        c = II (c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */

        b = II (b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */

        a = II (a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */

        d = II (d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */

        c = II (c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */

        b = II (b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */

        a = II (a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */

        d = II (d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */

        c = II (c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */

        b = II (b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */



        state[0] += a;

        state[1] += b;

        state[2] += c;

        state[3] += d;

    }



    /* Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的，*/

    /* 只拆低32bit，以适应原始C实现的用途. */

    private void Encode (byte[] output, long[] input, int len)

    {

        int i, j;

        for (i = 0, j = 0; j < len; i++, j += 4)

        {

            output[j] = (byte)(input[i] & 0xffL);

            output[j + 1] = (byte)((input[i] >>> 8) & 0xffL);

            output[j + 2] = (byte)((input[i] >>> 16) & 0xffL);

            output[j + 3] = (byte)((input[i] >>> 24) & 0xffL);

        }

    }



    /* Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，*/

    /* 只合成低32bit，高32bit清零，以适应原始C实现的用途. */

    private void Decode (long[] output, byte[] input, int len)

    {

        int i, j;

        for (i = 0, j = 0; j < len; i++, j += 4)

                output[i] = b2iu(input[j]) |

                        (b2iu(input[j + 1]) << 8) |

                        (b2iu(input[j + 2]) << 16) |

                        (b2iu(input[j + 3]) << 24);

        return;

    }



    /* b2iu是一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算 */

    public static long b2iu(byte b)

    {

        return b < 0 ? b & 0x7F + 128 : b;

    }



    /* byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，*/

    /* 因为java中的byte的toString无法实现这一点，我们又没有C语言中的sprintf(outbuf,"%02X",ib). */

    public static String byteHEX(byte ib)

    {

        /* if want to output normal letter please user DigitNormal */

        char[] DigitNormal = { '0','1','2','3','4','5','6','7','8','9',

        'a','b','c','d','e','f'};

        /* if want to output capitalization letter please user DigitCap */

        /* char[] DigitCap = { '0','1','2','3','4','5','6','7','8','9',

        'A','B','C','D','E','F' }; */

        char [] ob = new char[2];

        ob[0] = DigitNormal[(ib >>> 4) & 0X0F];

        /* ob[0] = DigitCap[(ib >>> 4) & 0X0F]; */

        ob[1] = DigitNormal[ib & 0X0F];

        /* ob[1] = DigitCap[ib & 0X0F]; */

        String s = new String(ob);

        return s;

    }

    public static void main(String[] args)
    {
        MD5 md5 = new MD5();

        String testStr = md5.getMD5ofStr("1");
        System.out.println("测试MD5,长度::" + testStr.length());
        System.out.println("测试MD5,加密后内容::" + testStr);
        System.out.println("测试MD5,加密后内容2::" + md5.getMD5ofStr("23423").equals(testStr));


    }

}
